Friday, July 31, 2009

In one of the parks where I like to go for walks, there are tons of blackberry bushes. They line the path for quite a ways but then there is a whole uncut field that is chock full of blackberry bushes. There are so many of them, it almost seems like somebody planted them on purpose, except they're growing every which way and not in rows or even the remnants of rows. They're just everywhere. And they're starting to ripen.

I used to get blackberries mixed up with black raspberries -- which are magnificent and may be my favorite berry.

Black raspberries look like name suggests, raspberries that are black. Beyond the nomenclature, you can also tell the difference because compared to blackberries, the black raspberries' seed knobs -- the term for that is drupelets -- are much smaller and more tightly packed.

Blackberries. You can see how the drupelets (seed knobs) are much larger in these than they are in the black raspberries.
(Photo by your Apple Lady)

Now that we've got the differences between the two straightened out, here are some facts about blackberries:

Blackberries are a member of the rose family. To be fair, the rose family is very large.

Blackberries grow wild in North America, but they are cultivated and grown commercially in Europe, Africa, and Asia, as well as North America.

Blackberries are sometimes also called brambleberries. But really that word "bramble" can refer to any of a slew of fruits that produce long vines with thorns -- raspberries, loganberries, boysenberries, dewberries, as well as blackberries, to name a few.

This branch with blackberries growing all over it had been knocked over onto the ground. But it gives you a good look at the woody cane on which these things grow. I don't know whether you can see them or not, but there are also small, thin thorns that grow on these bushes. They might be small, but those thorns can scrape you up pretty good.
(Photo by the Apple Lady)

Blackberries, like raspberries, are an aggregate fruit. This means they have lots of drupelets (knobs of fruit surrounding a seed) that are ganged together to form one larger fruit.

Blackberries also have a tough center core, which is called the receptacle. Just as the core of a pineapple is tough and woody and has less flavor, so too is the receptacle of a blackberry. The larger the blackberry, the bigger the receptacle.

Raspberries also have a receptacle, but theirs doesn't come away with the fruit; it stays on the plant.

Because of its receptacle plus all the seeds, up to 20% of a blackberry is fiber, which gives it one of the highest fiber contents of all fruits.

Like any dark fruit, blackberries are very high in antioxidants. So eating them regularly may be helpful in guarding against various forms of cancer or cardiovascular disease.

Many moons ago in the Pacific Northwest, people used to grind up the blackberry canes to make a powder that they used to treat toothache pain. I don't know whether it worked, only that they used to do it.

If you studied the taxonomy of blackberries, you would be called a batologist. And you would have a surprising amount of work; there are over 1,000 species of blackberry. Here are some of them:

arctic blackberry

bristly Oswego blackberry

Himalayan blackberry

Tampa blackberry

Baton Rouge blackberry

shrubby blackberry

Some especially big blackberries. They're also longer and pointier than a lot of the other blackberries I took photos of. I'm guessing they're a different species. Who knows how many different blackberry species are growing in this blackberry metropolis.
(Photo by the Apple Lady)

This is only a fraction of the blackberry bushes growing and making fruit in this park. Multiply this amount of berries on this number of branches by a couple thousand and you'll get the idea.
(Photo by the Apple Lady)

There were so many blackberries in this park, I couldn't resist. I picked some. I left some for the birds and the animals -- I saw a robin eating one off the bush -- but I picked a good amount.

When picking blackberries, or any fruit, the fruit should come away easily when you pull on it. If you have to tug or twist to get it off the branch, it's not ripe yet. Leave it and try another, which will be sweeter.

The final haul. Yum.
(Photo by the Apple Lady)

Once I got my blackberries home, I had a plan for them. I took about a third of what's in that strainer there, rinsed them, and put them in a little pot with a healthy squirt of lemon juice and a couple tablespoons of sugar. I heated them up and smashed them as much as I could with a wooden spoon. Those receptacles just did not want to soften. But soon I turned those berries into a saucy sauce.

Then I got a little round spongecake (thanks, grocery store) and poured that sauce over the sponge cake. Put some more of the fresh berries over the sauce, plus some good ol' Cool Whip and a final sprinkling of fresh berries, and there you have the Blackberry Dessert Extravaganza. Delicious.

My blackberry dessert. I call it Lisa Marie.
(Photo by the Apple Lady)

If you want to freeze blackberries, don't wash them first. They'll all stick together when they freeze and then turn to mush when you thaw them.

Instead, freeze them without rinsing. If you can, lay them on a cookie sheet so they're not touching each other, and once they're frozen you can tumble the little frozen fellows into a Ziploc bag or some other container.

If you don't have room in your freezer for an entire cookie sheet, you can put the berries straight into the container. But they might still stick together when they freeze.

Also be sure to leave some extra room in the container. Berries are mostly water, and water expands when it freezes.

P.S. In answer to Mark's question (see the comments), yes, the BlackBerry handheld phone is named after blackberries the fruit.

The company that makes the BlackBerry (Research in Motion, or RIM, based in Canada) hired a marketing company that specializes in creating brands. One of the guys at this company, Lexicon Branding, thought that the keyboard buttons looked like strawberry seeds, so maybe it should be called a strawberry.

From there, they considered lots of fruit names including "melon" and also some vegetables but discarded those. Can you imagine calling your fancy little device a melon?

Finally they settled on blackberry because the device was black, and the word was fun to say.

P.P.S. The name for the short-distance wireless connectivity protocol, Bluetooth, has a much more exotic history. And it sort of involves berries.

One of the founders of Bluetooth, Jim Kardach, was at a business meeting when a guy named Sven Mathesson who worked for Ericsson mentioned a Danish king named Harald Bluetooth.

After Kardach got home, he got a book of Danish history and looked up this Bluetooth person (ah, research!).

The short version of the king's story is this: Harald Blåtand ("Bluetooth" in English), lived in the late 10th century. He was named Blåtand, which means "dark complexion," because he had dark hair, which was unusual among the Danes. Some people like to say that he was called Blåtand because he liked to eat blueberries which stained his teeth, but that would take a lot of blueberries to stain your teeth permanently.

The reason Kardach settled on Bluetooth as the name for his device is because the thing Harald Blåtand is famous for is uniting Denmark and Norway, and he converted the Danes to Christianity. I'm not sure why converting people to Christianity was relevant, but Kardach thought it was, as well as the fact that Blåtand had united two countries. His product helped to bring people together, so he decided Bluetooth would be a good name for it.

The flying part of the phrase comes from ships' flags. In the 1700s, it became the practice for ships that were victorious in a sea battle to return to port with the flags of their home country flying from every mast of the ship; that is, triumphantly.

This replica of an 18th century gun ship is not flying any flags. In sailing language this means, "This ship has surrendered," or "This ship belongs to no country." It's not a good sign. Most ships fly at least one flag to tell other ships who they are. Since I saw a lot of images of ships with no flags, I bet whoever is in charge of this ship doesn't realize they're sending out bad signals by not flying any flag.(Photo from the Port of Redwood City)

This is a 17th century Dutch ship, as depicted by a Japanese artist from that time. Those are national and royal flags and banners of the Netherlands. Flying all those flags in front of people from another country is like using allcaps in flag language to shout: HA HA SUCKERS, THIS IS OUR SHIP, LA LA LA LA! Flying all of your flags as you sail into your home port is like shouting, WOO-HOO, WE WON! BREAK OUT THE CASKS OF WINE!(Image from Japan Probe)

Taken all together, "to come through it with flying colors" means that you'll be victorious in your pursuit. You may have to work hard (battle) for that victory but in the end it will be a complete (flags from all masts) success.

Or rather than having to work at it, you might sail through it. Har har.

When raindrops first form and drop out of clouds, they are very large -- sometimes as big as baseballs. They are also nicely spherical due to the surface tension inherent in water.

But as raindrops fall, air resistance drags on the drops and distorts them. We typically represent that distortion as a teardrop because that's the shape they make when they're hanging off something here on the ground. But in the air, raindrops actually take on other shapes that are more like pancakes, parachutes, or broken grocery bags.

What happens to raindrops as they fall and the shapes they make. These photos appeared in a study published this week.(Photo by Emmanuel Villermaux, sourced from Science News)

Each raindrop, still falling, reaches a point where the air resistance is so great that the drop flattens out and then bursts. What hits the earth, then, are the fragments of larger raindrops that have exploded on the way down.

Very small droplets, those with a radius of 0.014 cm, remain spherical the whole way down.

There's another fact about raindrops that may also be related to the way they break up on the way down. You would think that larger raindrops fall faster than smaller raindrops; i.e., the force of gravity acting on an object with more mass would give it greater acceleration than a smaller object. However, two researchers from Michigan Tech University discovered that some smaller raindrops actually fall faster than larger drops.

Using a spectrophotometer, they analyzed 64,000 raindrops during rainfalls. They discovered clusters of smaller drops that were not only falling faster than larger drops, but they were in fact traveling faster than mathematical formulas had predicted was even possible for their size.

They think that when the larger rain drops break up, the resulting smaller fragments continue to travel at the rate they were falling when they used to be bigger. Because not all small raindrops are the result of a ruptured larger raindrop but were small to begin with, this would explain why not all small raindrops travel faster than the big ones.

But why the broken-up raindrops should maintain the speed they had before they broke up, I don't know and as far as I can tell, neither do the researchers.

They do think, though, that weather forecasters have been overestimating rainfall for years. Meteorological software that predicts rainfall has been designed based on the assumption that larger raindrops always fall faster than the smaller ones. That has led meteorologists to estimate higher numbers of large raindrops, and thus a greater amount of overall rain.

COMPOSITION

You probably remember from your elementary school science class that raindrops first form around a particle of dust.

Once they've formed, raindrops grow larger as the wind turbulence in the cloud where they were born whips them around and bumps them into each other.

What's in a raindrop varies depending on where the rain is falling. If it's falling over oceans, the raindrop will have more salt in it. If it's falling over cities with lots of pollution, it might have higher levels of acids. But here are some of the things that have been found and are probably present in most raindrops:

Water

Salt

Dust

Smoke particles

Pollen

SOx (sulfuric acids, primary component of acid rain)

NO2 (nitrogen dioxide, a toxic air pollutant)

NH3 (ammonia)

Hydrogen

Calcium

Magnesium

Potassium

Sodium

Nitrates

Chlorine

Fluorine

Lead

Iron

Bromine

Manganese

Vanadium (metal that comes from minerals)

Aluminum

Not entirely a happy list, but that's a lot of stuff in one raindrop.

I thought I remembered learning at some point that little living organisms might be present in raindrops, but now I can't find anything that says that.

Raindrops do help disperse seeds, though. A falling raindrop may strike a plant and as the drop splashes, so do the seeds. Planting and watering all in one shot!

Friday, July 17, 2009

The other day I was walking home after a very nice walk in the woods, and I was approaching a busy intersection. A woman was standing at the corner with some friends, waiting for the light to change, and she laughed. Loudly enough that it echoed across the entire intersection.

It was such a carrying laugh it really struck me, and I suppose because I'd just come out of the woods and had been surrounded by all sorts of nature, I wondered, what is that laughter supposed to communicate? Like, if scientists were studying us as if we were just another animal out in the woods or someplace, what would they write in their scientific papers about what we humans are communicating to each other when we laugh?

Laughter, the scientists say, forms social bonds. It's a way of saying to the people around you, I'm a friend, not a foe.

During play, even aggressive play, if someone laughs, that signals to the other person, I'm only kidding around, don't take it seriously.

The person who hears the laughter experiences a reduction in tension. Specifically, the fight-or-flight response that we get in response to danger is significantly calmed down when we hear someone laugh.

One way that scientists know this is by observing other animals who also laugh. That's right, there are other animals who laugh: rats in response to tickling, dogs, chimps, and apes, to name a few.

The laughter sounds made by other animals are not as vocalized as ours are. Dogs make a sort of breathless panting when they laugh. Chimp laughter sounds like a handsaw cutting wood. Rats make high-pitched chirping whistles out of range of the human ear.

Researchers have observed that if a dog doesn't laugh during play, the other dogs will interpret it as aggressive and they will attack.

Here's proof that dogs know all about tickling. This Great Dane is tickling this baby, to the obvious enjoyment of both dog and baby.

Besides signaling I'm only having fun, laughter further develops social bonds through its contagiousness. When we hear someone laughing, we tend to start laughing at the very sound, whether we even know what it's about.

If Jane is laughing, and we all start laughing along with Jane, we're all sharing something together and, bing, we've formed a social bond.

By the way, the contagiousness of laughter is what's behind all the laugh tracks in TV shows. We are far more likely to laugh when we are in a group than when we are alone (even laughing gas has been shown to be less effective when taken with no one else present), and we are even more likely to laugh if we hear others doing it, too. So when we're watching some TV show all by ourselves and the jokes are pretty lame, we might not laugh at all. But if the show has a laugh track with sounds of lots of people laughing, we are more likely to laugh.

The down side of laughter is that sometimes we use it to laugh at other people. To mock them. This has the effect of excluding people, of telling them by our laughter that they are not as good as us in some way.

But I'm willing to wager that most of the time when we laugh at someone else, we're probably doing it in front of a group of others. I am guessing that we are really trying to form a bond with those other people by laughing at that one person we've identified as somehow not good enough. We're trying to say to the other people, "You and I are not like that low-life. We are better than him or her and so we get to laugh together at that person." It's not a happy way of forming a social bond, but it's a social bond regardless.

While we might want to do all we can induce other people to laugh, especially if we are TV producers, it is very hard to make someone laugh on command, or even simulate laughter.

In fact, laughter is defined as an uncontrollable response. At the same time, it is one whose goal is to form a bond with other people. Which is a pretty strange thing when you think about it. As one astute researcher pointed out, when was the last time you felt overcome by the urge to repeat, "Hello hello hello"?

We don't make just any sounds when we laugh; we make a series of very specific sounds. Almost always, they are vowel sounds repeated, as in "ha-ha-ha," or "he-he-he." Sometimes we might alter the first or the last vowel sound ("Ho-ha-ha-ha" or "Ha-ha-ha-he"), but rarely do we change up those vowel sounds within the sequence. "Ha-ho-ha-he-ho," for example, seems all wrong and even a little disorienting.

This laugh starts out with a bunch of ha's but then changes to lots of inhalations in a row. But still, it's a repeating pattern rather than an alternating one.

We also tend to repeat the vowel sounds at nearly the same time apart from each other. Ha-ha-ha-ha. In fact, one researcher has measured the time in between each "ha" to be an average of 210 milliseconds apart. Any faster (hahahahaha) or especially slower (ha . . . . ha . . . ha . . . ha) and we tend to distrust it.

To me, this woman's laugh sounds genuine at first, but then it seems to be too precise, or too well-spaced, and by the end, I distrust it.

We also usually begin laughing loudly and get quieter to the end of the vowel sounds, presumably as we run out of air. If you try to begin softly and get louder, it will feel and sound completely wrong.

(I'm noticing that, as I try these variant forms of laughing, the weirdness of it is making me laugh.)

(And, while I'm noticing that talking about laughing can induce laughs, the word itself is weird. I've noticed this while typing it so many times for this entry. So I looked it up. Etymologically speaking, it comes from words that look more or less insane:

hlæhhan [Old English]

hlihhan [Germanic]

hlæja [Old Norse]

cachinare [Latin]

kakhati [Sanskrit]

These words are all weird looking because they are trying to be onamotapoetic. That is, they are attempts to make words that sound like their meaning, in this case, laughter.)

Getting back to my point about how we use laughter, unlike how I've interrupted my own train of thought, we don't usually laugh in the middle of a sentence. If you listen to someone telling a joke to a group of people, you'll notice that 1) the person doing the telling is laughing a lot more than the listeners--signaling that it's a joke and trying to encourage them to laugh; 2) the person doing the telling/laughing will nearly always inject the laughter at the end of a sentence. "So I went to the butcher shop, right? (ha-ha) And standing at the counter, there was this dog. (ha-ha)" Et cetera.

The well-ordered nature of laughter -- you never would have thought that before -- suggests that laughter is a very deeply rooted neurological response. That is, as well as being all about communication and language and culture, it is so fundamentally so that it is physically encoded into our brains in a very specific way.

That's part of the uncontrollable response nature of laughter. But another sign that laughter is hard-wired into us is that every single culture of people on earth laughs. We all laugh in response to tickling. (That's called reflex laughter) And, I'm willing to bet, that since we all laugh when we are tickled, we would all recognize when someone is laughing in response to being tickled.

I'm going to suggest here to any negotiators who are trying to broker world peace in the midst of hugely tense cross-national talks, that everyone should take a break for a little tickle party. It's something everyone can agree on, it'll get everybody laughing, it'll take all the tension out of the room, and then maybe something could get accomplished.

My suggestion isn't so wacky. Various weighty international negotiations, such as those between Reagan & Gorbachev at Geneva or the Middle East peace talks that took place during the Clinton administration, often changed dramatically in tone once someone told a joke. In some cases, it was only after they got each other laughing that they were able to relax enough to reach some kind of agreement.

Another possible tool to break the ice in rocky negotiations could be showing cranky world leaders this video.

They might all start getting on each other's trampolines and yelling at each other like that, though.

This person sounds like she thought something was funny, laughed, thought about it some more and thought it was funny enough to laugh at it again. Which is exactly what I'm doing in response to that video.

However, you do have to be careful about telling jokes to people from other countries. Because reflex laughter is the only kind of laughter that is universal. Laughter in response to jokes is very culturally-dependent. If you try to tell a joke to somebody from another culture and you guess wrong at their sense of humor, you might not make them laugh, or worse, you could risk really offending them. So I think my tickling session idea has a far greater chance of success.

Or everybody could play a good game of Ha. We used to play this at slumber parties. (For the sake of clarity, I'm going to alternate genders here, but in real life, the slumber parties I went to were not co-ed.)

Person 1 lies down on the floor on her back. Person 2 lies down on his back, perpendicular to her, with his head on her stomach. Person 3 lies down on her back, perpendicular again and with her head on his stomach, and so on until everyone is lying down with his or her head on the stomach of someone else and also with someone's head on his or her stomach.

Person 1 begins by saying "Ha" a few times. Saying this word will push air out of Person 1's stomach so that Person 2's head starts moving up and down, sort of bouncing. It feels funny, so Person 2 will begin to laugh. That makes Person 3's head bounce up and down so Person 3 begins to laugh, and so on down the chain until everyone is laughing and everyone's head is bouncing.

I'm still thinking about the fact that everyone laughs at being tickled. Everyone. That's pretty powerful.

I wonder how different the world might be today if anyone had ever thought to tickle Hitler.

P.S. for some completely made-up fun based on a true fact (that rats laugh when tickled), stop by the Tickle-easy.

Sunday, July 12, 2009

I was going to begin this post by saying simply, "You know what I'm talking about." But when I did a little research into this, I discovered that not everyone does, in fact, experience the asparagus smell.

For roughly 40% of the population, in less than an hour of eating asparagus, our urine will acquire an odor like soggy eggs inside of old socks, and perhaps even take on a greenish tinge.

The rest of the population has no idea what I'm talking about.

The reason that some people have it and some people don't is genetics.

A gene is a bunch of DNA, some of which is active (exons), some of which is inactive (introns). Thousands of genes make up a chromosome, which is that X-shaped thing on the right.(Diagram from Wikipedia)

Scientists discovered back in the 1950s that a certain dominant gene is at work in the 40% whose urine changes smell after eating asparagus.

There is some debate about whether the 60% who don't experience The Asparagus Effect can't produce the odor or that they can't smell it. Recent research suggests that everyone's urine gets stinky from asparagus, but not everyone can smell it.

I'm very surprised that fewer people have it than those who don't. Because everyone I've ever discussed this phenomenon with knows exactly what I'm talking about. My sample must not be random enough. Population sample, I mean.

While scientists know that it's a dominant gene that makes you capable of doing this, they disagree about what compound produces that distinctive odor.

Generally, they agree that the compound is a combination of something present in the asparagus plus some digestive enzyme in the body that breaks down the asparagus.

Here is a list of the proposed culprits and a rough explanation of what they are:

Methyl mercaptan - same type of thing that makes skunks smelly.

Several S-methyl thioesters - results of sulfur reacting with an acid. The S stands for sulfur. Very smelly.

Asparagine - non-essential amino acid produced by asparagus reacting with other amino acids, and which is apparently also stinky.

Whichever of these compounds is responsible, they each involve sulfur or methane, or both. Sulfur smells like rotten eggs or burnt matches. Methane is the stinky stuff in the gas we all pass. So the stuff in the asparagus-laced urine is definitely stinky, whatever it is.

A hunk of sulfur, which came from a natural gas plant in North Dakota. It even looks stinky, doesn't it?(Image from the North Dakota Geological Survey)

So if your urine smells stinky after eating asparagus, be glad because it means your kidneys are working fine.

If you don't smell it, don't worry; you're probably one of the 60% who don't have that dominant stink-smelling gene.

P.S. I've been thinking about this some more, and I'm wondering if that initial research that came up with that 40% yes/60% no split was flawed. Because it sure seems like way more people say they smell it than don't. So I'm wondering if at least some of those 60% lied and said they couldn't smell it. Maybe they didn't want to admit their urine was stinky.

So, dear reader, if you have no idea what I'm talking about, if you have never experienced this at all before, would you be kind enough to post a comment to this entry and let the rest of us know that you really do exist? You would be advancing the cause of science!

I had assumed that bonfire came from bon (good) + fire. But no, the word comes from bone + fire, or a fire large enough to burn bones.

It is also possible that bone + fire was actually a variant of bane + fire, where bane was the Scottish word meaning beacon, or signal. So the fire would have to be large enough to send a signal to someone else. The English used bonfires to signal the approach of the Spanish Armada, for example. But very few people today refer to this concept of signaling.

Now, bonfire means any large fire built outdoors, often in celebration of an event. Or it could be a funeral pyre. Bit of a bipolar word, this.

Originally, bonfires were lit to celebrate all sorts of pagan festivals, some of them by Celtics to celebrate the summer solstice (roughly June 21), others by witches to celebrate the arrival of spring.

Records indicate that by the 15th century, bone fires were made using wood and the bones of sheep and oxen. This may have come from the concept of a "contribution fire," meaning fires that were built using all sorts of different materials that various people had contributed in order to build it.

In the 1600s, bonfires were lit to burn the bodies of those who had died from plague.

In the 1700s, when the church was all bent out of shape about suppressing heathens, bone fires were made to burn witches and heretics. But they'd done that before, at least as far back as the 1400s.

Then the church decided, as it so often has, on a compromise with pagan traditions and sanctioned the lighting of bonfires in celebration of particularly Christian events, such as the eve of St. John the Baptist's day (June 24) or the eve of St. Peter's day (June 29) . Which, not coincidentally, fall near the date of the summer solstice. The other major sanctioned feast day for bonfires was Christmas Eve (winter solstice-ish).

I can't find anybody who says such & such size fire equals a bonfire. But I have found out that various cities have ordinances about how big your bonfire can't be. The city of Hubbard, Ohio, for example, says that your bonfire can't be larger than 5 ft x 5 ft x 5 ft, it can't burn longer than 3 hours, and it has to be at least 50 feet away from a structure.

The University of Cincinnati requires you to tell the university at least 15 days before you're going to light your on-campus bonfire, you must have 2 "assistants" to monitor the fire, you must have fire extinguishers nearby, and you have to pay $75 before you can light it. They have the same size restrictions as Hubbard, Ohio. Only dry wood and a little paper allowed. No flammable liquids.

Lots of beaches in California allow bonfires, but they have rules too, including that you must build the bonfire in specially designed cement pits (3 ft in diameter), or otherwise make sure it's 100 feet from vegetation or dunes, you have to have a bucket to carry water to put out the fire, and you can't put out the fire by covering it with sand but must put it out with water.

A bonfire in West Belfast, Ireland, to protest Britain's internment policy of August 9. The primary materials used here, wooden pallets with nails in them, would be no-nos according to most municipal regulations.(Photo from cúisle mo chroí)

Other, more urban locations particularly in Europe are less precise about a bonfire's dimensions but only recommend keeping the bonfire to a manageable size, considering your neighbors and the smoke pollution they'll have to deal with, and not burning plastics or petroleum products that will unleash harmful chemicals.

In Doncaster, England, if you light a bonfire that exceeds their size limitations or that you allow to burn later than their calendar/schedule allows, you could be fined £5,000 or imprisoned for 6 months.

Guy Fawkes Day is traditionally celebrated by building big bonfires, but more and more locations are getting too nervous about the potential risks for injury posed by such huge fires, and they're not making the bonfires anymore. One town, instead of lighting a bonfire, showed a film of a previous year's bonfire.

So many rules about bonfires! That seems antithetical to the nature of bonfires.

In Newfoundland, Canada, they like bonfires. They build bonfires this big and invite teenagers from all across Canada to show up and meet each other.(Photo from SendtheFire.ca)

Perhaps the biggest bonfire occurs each year at Burning Man in Black Rock Desert, Nevada. People gather from all over to this harsh environment where they must bring their own food, water, and shelter. They also bring mementos of the past that they'd like to forget or otherwise offer up, and they stick their stuff all over this gigantic effigy. Then they burn it in what many people describe as a purgative, healing experience.(Photo from Boba's Adventures in the World)

If you see a bonfire in your dreams, supposedly this means you need to set a different goal for yourself or embark on a new path in your life.

Wednesday, July 1, 2009

Two faithful Daily Apple readers want to know about lightning bugs, or fireflies, and what's all that bioluminescence about. They guessed that it's about mating, but they'd like to know for sure. Good question, I say. And I want to know what causes that glow. Do they have little pools of phosphorus in there, or something?

Keep in mind, if you catch a firefly, it's only got two weeks or less to live, whether you keep it in the jar or not.(Photo from Firefly.org)

Fireflies are actually beetles.

There are about 2,000 different species of fireflies. Some flash off and on, some simply glow, some flash and dive to make glowing shapes in the air, and some don't glow at all.

Fireflies prefer moist places, so they tend to live in humid climates or near bodies of water. Some Asian fireflies spend their entire lives underwater.

More species of fireflies and more of each species live in Asia. So in Asia you'll see a lot more fireflies in one place, as in this photo of a berembang tree in Malaysia that is full of fireflies.(Photo from Malaysia Site)

Fireflies live all across the US, but west of Kansas you'll find only the ones that don't glow. Scientists don't know why the glowing fireflies prefer the eastern part of the country.

Three special substances combine in the cells of the photic organs. The three substances are

luciferin -- a pigment present only in fireflies and other bioluminescent creatures

luciferase -- enzyme that acts as a catalyst

ATP, or adenosine triphosphate -- a nucleotide that provides energy to cellular activities. We all have ATP in our cells.

(Luciferin and luciferase, by the way, don't have anything to do with the devil. Those words mean "light bearer," not devil. So don't go making fireflies into something evil because they're not.)

Those three substances react together to make two new substances, and then one of those meets up with oxygen, light is produced.

What's pretty remarkable about this reaction is that nearly 100% of the energy produced is in the form of light. Hardly any of it is heat. By comparison, only 10% of a light bulb's energy is in the form of light and 90% is heat. This is why the fireflies don't overheat when their taillights keep flashing on and off.

Scientists think that the flashing happens when fireflies control the flow of oxygen into the photic organ. When the restrict the flow of oxygen, the light shuts off. Turn on the oxygen, the light goes on.

Speaking of the flashing, each species has a different blinking pattern. So if you see a firefly that blinks in one pattern and another one nearby that flashes a different pattern, chances are, those are two different species.

If you watch long enough, you can pick up their blinking pattern. And if you have a penlight and blink it in the same pattern, a firefly will flash you that pattern back.

And yes, the purpose of the blinking is so that the fireflies can find potential mates.

Firefly mating is actually pretty intense. Fireflies live for two years underground as larvae, and then when they come up into the air as adults, they've got two weeks to live and they spend it looking for mates.

The fireflies doing all the flashing are males. (No pun intended.) The females stay on the ground and watch. When they're interested in somebody, they flash a single pulse. The male will blink his pattern back, and a call & response goes on for a while.

A female might flash her single pulse with as many as 10 males in an evening. But ultimately, she'll choose only one--the one with whom she has had the most call & response exchanges.

How she chooses which male may have something to do with the male's ability to provide food.

Male fireflies, like a lot of invertebrate species, produce packages of protein with their sperm. Eggs that are fertilized with sperm that has lots of protein do much better than those with less sperm-protein. So scientists think that female fireflies are interpreting the male firefly signals to try to find the males that can give them the biggest protein package.

But firefly flashing is a subtle art. Males that flash brightest or fastest or longest are sometimes preferred by the ladies. But those superlative males are also the biggest target for their main predator, the Photuris, which pounces on fireflies, sucks the blood out of them, and casts their husks aside. So scientists think this is why some females prefer males that aren't always so flashy--they live longer.

When a male and female firefly do hook up, they mate with each other all through the night until dawn. Then the couples will split up and the females will burrow into the grass and lay their eggs.

Firefly larvae also produce a glow. But larvae are certainly not old enough to mate. So scientists think that another purpose of the glow might be to warn potential predators that fireflies taste very bitter. (I always wonder how scientists know this sort of thing. Do they eat the fireflies themselves? And how do they know that what tastes bitter to humans will also taste bitter to birds or other bugs?)

There are a few other beetles besides fireflies that are bioluminescent. Some click beetles can glow, and a few beetles in the phengodid family, as well as a few other small families of beetles.

I just want to point out a little coincidence here. The Daily Apple reader who asked me about this topic did so on my birthday. The article that is the primary source for this Apple was published on my birthday. A little synchronized glowing, yes?

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